Does obesity affect outcomes after hip arthroscopy? A cohort analysis.

BACKGROUND: Obesity presents a challenging problem in surgical treatment and has led to poorer postoperative outcomes. The purpose of this study was to evaluate whether hip arthroscopy in the obese patient influences postoperative clinical and patient-reported outcome scores.

METHODS: From February 2008 to February 2012, data were collected prospectively on all patients undergoing primary hip arthroscopy. A total of 680 patients were included. All patients were assessed preoperatively and postoperatively with four patient-reported outcome measures. Pain was estimated on the visual analog scale. The patient satisfaction score was measured. Three groups were stratified by body mass index. The non-obese group, those with a body mass index of <30 kg/m(2) (mean, 23.61 kg/m(2)), included 562 patients with a mean age of 34.78 years. The class-I obese group, those with a body mass index of ≥30 to 34.9 kg/m(2) (mean, 33.85 kg/m(2)), included ninety-four patients with a mean age of 44.02 years. The class-II obese group, those with a body mass index of ≥35 to 39.9 kg/m(2) (mean, 39.11 kg/m(2)), included twenty-four patients with a mean age of 39.33 years.

RESULTS: In the non-obese group, the score improvement from the preoperative assessment to the two-year follow-up visit was 63.41 to 83.81 points for the modified Harris hip score, 60.86 to 83.62 points for the Non-Arthritic Hip Score, 66.24 to 86.24 points for the Hip Outcome Score Activities of Daily Living, and 44.01 to 73.26 points for the Hip Outcome Score Sport-Specific Subscale. In the class-I obese group, the score improvement from the preoperative assessment to the two-year follow-up visit was 54.81 to 75.95 points for the modified Harris hip score, 48.98 to 72.51 points for the Non-Arthritic Hip Score, 53.22 to 72.99 points for the Hip Outcome Score Activities of Daily Living, and 30.56 to 60.75 points for the Hip Outcome Score Sport-Specific Subscale. In the class-II obese group, the score improvement from the preoperative assessment to the two-year follow-up visit was 50.81 to 80.01 points for the modified Harris hip score, 42.36 to 72.50 points for the Non-Arthritic Hip Score, 48.11 to 74.73 points for the Hip Outcome Score Activities of Daily Living, and 28.25 to 62.56 points for the Hip Outcome Score Sport-Specific Subscale. Traction time did not vary significantly between groups (p < 0.05).

CONCLUSIONS: Our study demonstrated that obese patients started with lower absolute scores preoperatively and ended with lower overall absolute postoperative scores. However, obese patients showed substantial benefit from hip arthroscopy and demonstrated a degree of improvement that was similar to that of the control non-obese group.